Sina (SINA -6.7%) sells off after DigiCha reports all users of Sina's wildly popular Weibo...

Sina (SINA-6.7%) sells off after DigiCha reports all users of Sina's wildly popular Weibo microblogging platform will be required to register with their real names as of March 16. It's added that since new users have been required to provide their real names, Weibo's registration rate has fallen to 2.5M/month. It's speculated some of this decline may be due to a lack of "zombie/spam accounts" being registered.